Crossover Cap Install - Please Help

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rockadanny

Crossover Cap Install - Please Help
« on: 29 Jan 2026, 01:17 pm »
Trying a new capacitor Vcap ODAM in Leonidis crossovers on my Pure Audio Project Trio15 Horn1 speakers. Install instructions state, "The short lead indicates the outermost foil, and should be connected to the lowest impedance path to ground."  How do I determine that?

FullRangeMan

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Re: Crossover Cap Install - Please Help
« Reply #1 on: 29 Jan 2026, 06:30 pm »
You will need an multimeter to measure that impedance/resistance.

rockadanny

Re: Crossover Cap Install - Please Help
« Reply #2 on: 29 Jan 2026, 07:33 pm »
@FullRangeMan - So simply measure resistance (ohms) at each of the two connection points individually to ground to see which is lowest?

nlitworld

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Re: Crossover Cap Install - Please Help
« Reply #3 on: 29 Jan 2026, 08:36 pm »
If you have a diagram or photo, we may be able to troubleshoot from there as well. Typically found it's the side closest to driver, but if crossover has a bunch of extra parts that could change.

FullRangeMan

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Re: Crossover Cap Install - Please Help
« Reply #4 on: 30 Jan 2026, 10:42 am »
@FullRangeMan - So simply measure resistance (ohms) at each of the two connection points individually to ground to see which is lowest?
Apparently so, but I'm not going to risk guessing without being in front of the equip and evaluating the whole context.

poseidonsvoice

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Re: Crossover Cap Install - Please Help
« Reply #5 on: 30 Jan 2026, 11:41 am »
Rockadanny,

You should be able to find the installation notes for the VCAP ODAM’s online, it’s on Chris’ website. That being said, you don’t need to use multimeters, etc…and such. Just remember the short lead is the lead of the outer foil. If you want to really identify the outer foil properly, then you need an oscilloscope. But since Chris has already informed you, that takes the guess work out.

If you have the crossover schematic handy, it will be very useful. Unless the manufacturer has allowed you to post it publicly then do not.

Here is the advice:

In loudspeaker crossover applications, if the <insert obscenely expensive cap name here> is in series, like feeding a tweeter, the outer foil connects to the input binding post and the other lead connects to the tweeter. Where the <insert obscenely expensive cap name here> is in parallel, as typically used for woofers, the outside foil connects to the speaker connection that connects to the input binding post and the other lead connects to the other speaker terminal. Follow these same rules for midrange connections where you will have
a combination of both.

Just remember these are not monumental differences and nothing bad happens if you were to install the cap the other way without regards to outer or inner foils. It’s not like your ears will start bleeding.

Best,
Anand.

Speedskater

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Re: Crossover Cap Install - Please Help
« Reply #6 on: 30 Jan 2026, 12:39 pm »
Is this a speaker level crossover or an interconnect level crossover?

rockadanny

Re: Crossover Cap Install - Please Help
« Reply #7 on: 31 Jan 2026, 12:32 am »
Thank you all for the assistance.
Can't find a schematic yet.
Speaker level crossover.

Speedskater

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Re: Crossover Cap Install - Please Help
« Reply #8 on: 31 Jan 2026, 12:55 pm »
Outer foil positioning shouldn't matter on a low impedance speaker level crossover.
Only on low signal level high impedance circuits.

rockadanny

Re: Crossover Cap Install - Please Help
« Reply #9 on: 31 Jan 2026, 02:54 pm »
Got some advice on how to configure their installation. Swapped 'em in. They'd already been run in for about 50 hrs at the factory, IIRC. I ran them in for 8 hours more, then sat to listen a bit.

I REALLY like how they sound! Excellent separation of instruments without sounding "Hi-Fi"-ish. No crescendo cringe moments (although Iggy And The Stooges have yet to make an appearance  :lol: ). More effortless presentation. No diffusion at all. More detail without getting thin or clinical, just a "pure" flow of music. Not warm, but not cool either, just proper sound.

Per your comments it sounds like it doesn't make much difference which way they're installed anyway, so I have no desire to fiddle-fart around with that. Plus, I trust the advice I was given. Also, It's difficult for me physically these days to get on the ground and mess with crossover boards too much. And, I don't want to risk bending the leads this way and that and back again too much, which I must also do to an adjoining resistor as these caps are big (33 mfd). Thus, I've shifted into "enjoy the music" mode now. Snowing today in the ATL, so no travelling about, so might as well listen to more music! Yee-haa! Lucky me!

Thank you all for the replies!  :thumb: